In recent years, more and more electronic devices such as tablet personal computers and portable digital assistants include touchscreens to improve operability and usability. A user can enter information on a position on a display surface of the liquid crystal panel by touching the display surface of the liquid crystal panel with a finger or a stylus. According to this configuration, the user can perform intuitive operation, that is, the user can perform operation with direct feeling as if he or she directly touches an image displayed on the liquid crystal panel. A display panel with a position inputting function of such a touchscreen is disclosed in Patent Document 1.
Patent Document 1 discloses a display device including a display unit, a touch detection unit, and a driver unit. The driver unit drives the display unit to sequentially display M horizontal lines in each of plural unit driving periods forming one frame period and drives the touch detection unit in N touch detection periods provided in each unit driving period. N is smaller than M. In the display device, the M horizontal lines are sequentially displayed in the unit driving period and the touch detection unit is driven in the N touch detection periods provided in each unit driving period.